Key-lever spring-lock



A. J. PRUSZYNSK AND A. 0. H. EBERT.

KEY LEVER SPRING LOCK.

APPLICATION FILED FEB. 4. 1918.

SPRllNG-JOCK.

Specification of Letters Eatent. Patqsmtgd Emily 129 119210 Applicationtiled February e, 191e., Serial No. M5238.

.To all whom t may concern;

'r D Be 1t lmown that we, Anonrr-r el. r nuszrn'- snr and Amann (lL` -l.Eisner, citizens ot' the'llnited States, residing at Chicago, in thecounty of @ook and State ot illinois, and at l/Voodstock, in the countyorp Mc- Henry and State of llllinois, respectively, have inventedcertain new and useful lmprovements in Key-Lever Springlnocks, of whichthe following is a specification.

This invention relates more particularly to the key lever constructionot 'a typewriter and to the means tor pivotally mounting and adjustingthe spring tension which is applied to the key lever.

iihre invention consists in the novel construction, combination andarrangement olf the parte,

ln the accompanying drawinglligure 1 is a side elevation ot a key leverwith a sectional view orD the pivotal mounting and spring tensionadjustment parts;

llig. 2 is a sectional view taken on line 2-2 ot Fig., 1e

'1t is necessary to provide an adjustment of the means for varying thespring tensionot typewriter key levers so that they may be uniformlyoperated, and it is desirable to provide a convenient means7 not onlyfor varying the tension applied to the key levers, but also for insuringthat this tension will be maintained. The principal object ot theinvention, therefore, 'is to provide a yielding pressure plate whichbears upon the spring tension adjustment screws for holding the screwsin any adjusted position and to prevent their dislodgment undercontinued operation of the key levers.

lln the accompanying drawing, the numeral 1 designates generally atypewriter trame iii-which there is positioned a subirame having a keylever pivoting trame part 2 and a trarne part 3 in which are pivoted thetype-bar sub-levers d.

rll'ie trame part 2 is formed with an upstanding portion 5, in which arevertical slots 6, with a horizontal groove l opening from the rear andextending transversely of the' slots 6 for seating a pivoting wire 8. lnline with each of the slots 6 is a vertical perforation '9, having abeveled upper edge 109 and a lower threaded portion 11 in which anadjusting screw 12 is movable. A plurality oit key levers 13 aredisposed in the slots 6, and the rear end oieach key lever is formedwith a substantially vertical pivoting slot 1e which engages thepivoting wire rlFhe key levers are maintained in an upright position bythe slots 6 in which they are pivot/ed at the rear end and by slottedcomb 15 adjacent the :forward e1;- treniity thereof, and each one has apin 16 :tor actuating its euh-lever e, a wellknown manner. i

interposed between each key lever 13 and its tension adjusting screw 12is a spring 16,' the lower end of which is seated in recess 9), and theupper end oi which engages a projection 17 formed on the lower edge ofthe key lever for that purpose. riliis spring will normally hold the keylever upon its pivot 8, but in order to insure that the key lever willnot be disengaged trom the pivot a guard plate 18 is attached by meansof screws 19 to the trame portion 2 just below the lower edge of the keylever beneath the pivot wire 8 so that any abnormal depression ot thisend of the key lever is prevented by the guard plate, but so that theguard plate oders no obstruction whatever to the ordinary pivotal actionof the key lever.

Along the front edge of the frame part 2 is a ledge 20, and the upperedge of a pressure plate, having a plurality of spring tongues 22, isapplied to this ledge' so that the extremity of" each tongue bearsagainst the lower end of one of the adjusting screws 12, and as thispressure plate is preferably of spring metal, the tongues may be pressedagainst all of the adjusting screws in unison by means of a clampingplate 23 which forces the pressure plate 21 against the ledge 2O and thetongues 22 thereof against the extremities ot' the screws 12. rlhetongues being resilient it is obvious that any screw can be separatelyadjusted by means oi a screw-driver without relieving the tension of`the pressure plate; the tension ot the tongues is such that the screwsare held in place in any adjusted position. 'llhis tendency to becomeloose arises mostly under operating conditions due to the continued op-Oil eration ofthe key levers, but if a slight pressure is placed uponthe screws, such as that given by the spring tongues 22, they eXhiblt notendency whatever to become loose,-but will remainixed in any positiontowhich they are adjusted,`soz' that the tension placed on the springs 16may be varied and maintained as desired.

It is obvious that instead of making either' the pressure or clampingplates 21 and '23 apply to all of the Yadjustment screws-they maybe madein sections, and the same is also true of the guard plate 18. It-is alsoobvious that each screw can be rotated a whole or any 2. In atypewriter, a plurality of key levers, a tension spring for each of saidkey levers, an adjusting screw for each of said tension springs, andresilient means for separately holding each of said adjusting screws invarious positions of rotation, said re' silient means comprising aplurality of U- shaped spring tongues, one for each of said screws, eachof said tongues having its lateral face at the free end thereof arrangedto engage the side of its respective screw and to exert lateral pressureon said screw.

3. In ay typewriter, a plurality of pivoted key. levers, a perforatedframe part having slots in which the levers are pivoted, an adjustingscrew in the frame part for each lever, a. tension spring between eachscrew and its corresponding lever, and a tmember with separate springtongues one for engaging the end of each screw to hold it yieldingly inany adjusted position, each of said tongues being arranged with alateral face thereof resiliently held-against one of said screws.

4. The `combination with a frame part having an upper slotted portionand per? forationsin-line with the slots, of key levers pivoted 1n theslots and` overlyin the perforatlons, adjusting screws threa ed in theperforations and projecting therefrom,

springs interposed between the screws and the levers, and means forholding the screws 1n adjusted positions comprising a platewlthaplurality of'resilienttongues, one for engaging each screw, each ofsaidy tongues bein-g arranged with a lateral face thereof pressedagainst its respective screw,

' Las-ipse tongues, one for engaging each of the adj usting screws tohold them in anyrotatable position, each tongue having a lateral yfacethereof resiliently held against its respec- -tive adjusting screw tohold said screw in any osition of rotation.

6. n a typewriter, pivoted key levers, tension springs and adjustingscrews therefor, a plate with a plurality of spring tongues, one foreach of the adjusting screws, and means for clamping the plate with thetongues against the screws, each tongue having a lateral facether'eofresiliently held against its respective adjusting screw to hold saidscrew in any position of rotation.

7. In a typewriter, key levers, -a frame part in which the levers arepivoted having perforations below the levers which are beveled at theedge adjacent the levers, and coil springs disposed in` the perforationsand bearing against the levers the beveled edges preventing the springsfrom catching the edges when the levers are operated.

8. In a typewriter, the combinaton with a frame part, key levers pivotedtherein, tension springs and adjusting screws therefor projecting fromthe frame part, a member with a plurality of, spring tongues bent overat the end and adapted fto engage the ends of the screws, and a'clamping plate for 10. In a typewriter; a frame part having i 1anupwardly extending slotted portion, with a horizontal groove extendingacross the slots; a key lever disposed inthe slot having a substantiallyvertical pivoting slot; a pivot therefor seated in said groove; a 'ten'-sion adjusting means for the lever comprising a spring, an adjustingscrew and means including a spring-tongued plate for holding the screwin any rotatably adjustable positiOn, the tongues of said plate beingarranged wth their lateral faces resiliently pressed against theirrespectivescrews; and means for preventing the disengagement of thelever from its pivot.

11. The combination with key levers, of a frame part in which they arepivoted having 4underlying perforations and a` ledge at the l front,tension springs and adjusting screws for the www sem new@ sepamtey tobind. them yieldglg" each having 'Lsi and. faally against @ne Side @fesmmmy Wwfem nam@ Q0 this specification, his BGL January, A. D. i918.

ADL* 'H Q NSKE. En testimony Whefeu: have signed mame it@ @hasspemcatmm, omhls isb day January A., D. 1931i Y ALFL

